Economists surveyed by MarketWatch forecast claims to rise to 351,000 from a revised 342,000 in the prior week. The increase may have been partly influenced by a federal holiday on Monday — full claims data for four states including California and Virginia were not completed on time and had to be estimated.

Initial claims, a rough gauge of layoffs, have mostly stayed north of 360,000 over the past year. Although they've occasionally fallen below that level, claims have always bounced back up.

If claims can break below that threshold and stay there, it would suggest companies have accelerated hiring or are cutting even fewer workers. By and large, the economy has added just slightly more than 175,000 jobs a month in the past two years.

"Looking through the weekly volatility, a stable level of claims as of late is consistent with the familiar, moderate improvement in the labor market," said Yelena Shulyatyeva, an economist at BNP Paribas.

Yet economists caution that claims could get whipsawed again, as they often do, if Washington proceeds with a sequester that requires the federal government to cut as much as $85 billion in spending in the next six months. That could result in workers being temporarily furloughed or laid off, making them eligible for jobless benefits.

The monthly average of jobless claims, a more accurate number that smooths out weekly volatility, rose by 8,000 to 360,750. That's the highest level since the first week of January.